The present invention concerns an axial flow machine or blower having a rotor with adjustable blades, and particularly relates to the lubrication of the pathway of rotation of the struts for the rotor blades.
An axial flow machine, and particularly a blower, comprises a closed housing and rotor blades supported externally of the housing for being rotated together with the housing. The blades are supported by respective struts which extend into the housing. The orientation of the rotor blades with respect to the housing is adjusted by rotation of the respective struts. The struts are adjusted in their rotation by an axially displaceable adjustment part in the housing with which each of the struts is in engagement, such that axial displacement of the adjustment part causes rotation of the struts and of the blades for facilitating simultaneous adjustment of the orientation of all of the blades.
To each of the struts is attached a swing lever pin that is offset from the strut in the manner of a crank. Each swing lever pin is carried in a respective slide block, with respect to which the pin is rotatable. The slide blocks are in turn received in a peripheral annular groove in the adjustment part. The axial displacement of the adjustment part moves the slide blocks, causing the struts and blades to rotate to different orientations.
Within the enclosed housing, the struts are supported not only at the slide blocks, but at one or more support bearings along the length of the strut, which permit rotation of the struts to adjust the blade orientations.
Such an axial flow machine or blower is known from U.S. Pat. No. 4,046,486. In that machine, a ring of oil is established on the inner circumference of the housing during operation. In this way, satisfactory lubrication of the strut bearings is obtained. However, the lubrication of the slide blocks in the groove of the adjustment part is unsatisfactory. These blocks have oil flow over them only at irregular intervals, namely the oil which collects in the bottom of the housing only when the axial blower is shut off.